Ultrasonic instruments, including both hollow core and solid core instruments, are used for the safe and effective treatment of many medical conditions. Ultrasonic instruments, and particularly solid core ultrasonic instruments, are advantageous because they may be used to cut and/or coagulate organic tissue using energy in the form of mechanical vibrations transmitted to a surgical end-effector at ultrasonic frequencies. Ultrasonic vibrations, when transmitted to organic tissue at suitable energy levels and using a suitable end-effector, may be used to cut, dissect, or cauterize tissue. Ultrasonic instruments utilizing solid core technology are particularly advantageous because of the amount of ultrasonic energy which may be transmitted from the ultrasonic transducer through the waveguide to the surgical end-effector. Such instruments are particularly suited for use in minimally invasive procedures, such as endoscopic or laparoscopic procedures, wherein the end-effector is passed through a trocar to reach the surgical site.
Solid core ultrasonic instruments adapted for use in surgery and, more particularly, for use in minimally invasive surgery, are well known in the art. For example, U.S. Pat. No. 5,322,055, and International publication number WO 98/14126 illustrate clamp coagulator surgical instruments which utilize solid core ultrasonic technology. Clamp coagulators such as those illustrated utilize clamp arms to apply pressure to tissue, forcing contact between tissue and the distal end of the ultrasonic waveguide which is generally referred to as the blade.
The clamp arm of clamp coagulator instruments such as those described in U.S. Pat. No. 5,322,055 generally include a pad, often made from a polymer, to limit contact between the active ultrasonic waveguide and the clamp arm. In such instruments, the clamp pad may become worn or contaminated during use in surgical procedures, requiring the entire instrument to be discarded. Thus, it would be advantageous to provide a simple and cost effective way to replace worn or contaminated clamp pads. It would also be advantageous to provide a means for attaching sterile clamp pads during surgical procedures. It would further be advantageous to provide ultrasonic clamp coagulating instruments with removeable and replaceable clamp arms and clamp arm/pad combinations. It would also be advantageous to provide ultrasonic clamp coagulators particularly adapted to allow simple removal and replacement of clamp arms.